1. Field of the Invention
The present invention relates to single use containers including applicator. In particular, the present invention is directed to blow-fill-sealed single use containers for storing and dispensing a fluid substance.
2. Description of the Related Technology
Measured amounts of various fluid substances are commonly dispensed in relatively small packages, often for single use. The fluids include a wide variety of products, including food products such as condiments, personal care products such as shampoos and skin creams, cleaning products such as various packaged “wipes,” and pharmaceutical products such as medications.
A popular package is a single serving package formed from two sheets of foil or plastic, superimposed over one another and sealed together around the periphery. The package has a notch or other means to facilitate tearing one edge away from the container. The user tears open the container, dispenses the fluid, and disposes of the container. One such example is a single serving ketchup package.
Such packages, while relatively simple and inexpensive, have several drawbacks. First, the package contains no means for directing or spreading the dispensed fluid. In particular, thick fluids tend to be dispensed from this type of package as a bolus, leaving the user to find a way to spread the bolus. Alternatively, thin fluids tend to be dispensed from this type of package in a difficult to control stream.
Second, this type of package can be quite difficult to open, particularly for those with arthritic hands or otherwise compromised grip strength. This difficulty is at least in part caused by the fact that, in the conventional designs of this package, it is necessary to tear away one of the sidewalls of the package in order to release the contents. However, the same sidewall must be sufficiently strong to contain the contents of the package under normal handling conditions, which may include accidental compression. Even a small amount of moisture or skin oil on the surface of the package can make gripping and tearing the strong sidewall quite difficult. Frustrated users often use their teeth to open ostensibly manually “tear open” packages, presenting aesthetic and hygienic issues.
Third, the velocity of the fluid as it is expelled from the package varies with the viscosity of the fluid, the amount of sidewall opened and the pressure applied. When the package has only a pinpoint opening in its side, a relatively strong squeeze on the package can propel the low viscosity fluid within the package to quite some distance. This can create a nuisance for the user.
Improvements on various aspects of this type of package have been proposed. U.S. Pat. No. 5,577,851 discloses a sponge applicator attached to a tube dispenser that contains a quantity of a substance, such as painter's spackle, to be dispensed. After use, the sponge applicator is designed to be removed, cleaned, and returned to the tube dispenser. The reuse of the sponge applicator raises issues of potential hardening and chemical or bacterial deterioration of the sponge. This applicator is unsuitable for use with products such as those intended for human consumption, where reuse of the applicator may cause bacterial contamination. U.S. Pat. No. D363,377 similarly discloses an integral spreader, which provides a roller atop a dispensing container. The roller spreads the dispensed fluid, but is subject to the same cleaning and hygienic drawbacks.
Efforts to produce an integral spreading means suitable for single use containers have achieved mixed success. For example, U.S. Pat. No. 6,007,264 discloses a package comprising two superimposed sheets sealed together around their periphery, with the provision of peelable flaps along one edge of the package. The user peels back the flaps, pulling apart one sealed edge of the package and thus exposing the contents. The peeled back flaps, at an approximate 90-degree angle to the package, thereby provide a butterfly wing type spreader for spreading the contents. Such a design overcomes any need to clean or re-use the spreading device, as the entire package is disposable after use.
However, the successful implementation of this type of package depends largely on the viscosity of the fluid dispensed. For example, fluids with a high viscosity, such as ketchup or heavy creams, tend to be dispensed as a discrete bolus, whereupon they can be effectively smeared about the intended surface by the butterfly wings. When used with liquids of low fluid viscosity, such as some pharmaceutical preparations and other relatively thin liquids, such fluids tend to be dispensed from the opened package in a stream, as opposed to a bolus, and thus the fluids tend to run out of the flap or wing spreading area before they can be effectively spread.
To counter this undesirable propensity, the same patent discloses embodiments wherein an absorbent foam applicator is either applied in two pieces to the opposing flaps or is applied in a single piece bridging the flaps. Such embodiments are designed to provide an absorbent surface area to facilitate the spreading of the dispensed fluid. However, this design has achieved only marginal success because the separate foam applicators are ineffective in retarding the sudden flow of the fluid from the ruptured packaging.
U.S. Pat. No. 4,921,137 discloses a container with an enlarged ear-like structure that facilitates grip, including a channel portion within the ear-like structure to minimize the sudden gushing of contained substance under pressure, especially for substances with low viscosity. However, the container does not include any means for spreading a bolus of dispensed liquid.
U.S. Pat. No. 6,117,123 discloses a flexible container that provides for the storage and mixing of diluents and medicaments. The container incorporates multiple compartments, separated by preferentially peelable seals, in which the diluents and medicaments are stored. The peelable seals are ruptured by manipulation of the container to thereby mix the components together for delivery through standard I.V. equipment to a patient. The seals are constructed such that the seal between the diluent and medicament compartments is preferentially ruptured to allow the liquid medicament and diluent to be mixed before the combined solution is accessible for administration.
U.S. Pat. No. 6,902,335 discloses a dispensing container including a compartment, a chamber, and an applicator pad. The chamber and the compartment may be fabricated out of separate materials that are bonded together. It is preferred, however, that the chamber and the compartment be fabricated from the same material as a single structure separated into two sections by a frangible seal. The container is designed to contain a flowable substance that can be dispensed by applying pressure upon the compartment area, where the substance is stored. The pressure ruptures the frangible seal and expresses the substance into the chamber, behind the applicator. The expansion of the chamber walls and the resilience of the applicator pad allow the substance to spread out behind and into the applicator, where it is available to be expelled and applied. This container is suitable for high viscosity substances but substances with low viscosity may still be suddenly expelled through the applicator, when the pressure exerted on the compartment is not adequately controlled.
Thus, there remains a need for single-use containers that are sufficiently versatile to allow for dispensing of both high and low viscosity substances and which facilitate simple even spreading of the dispensed liquid substance.